Sulfonamide compounds are well known for their biological activity. Certain classes of sulfonamide derivatives are useful as herbicides while other classes are useful as anti-bacterial agents.
In EP-A-0411706 it is disclosed that sulfonamide compounds of the general formula ##STR3## in which A is a nitrogen atom or a group CR.sup.5, each of R.sup.1, R.sup.2, R.sup.3, and R.sup.5 is one of a range of moieties, and R.sup.4 is an optionally substituted alkyl, aralkyl, aryl or heterocyclic group, or salts thereof, exhibit herbicidal activity.
A class of sulfanomide derivatives has now been found which differ structurally from those disclosed in EP-A-0411706 in that the terminal group R.sup.4 has been replaced by a substituted amino group and which have useful herbicidal properties.